What is it?Paralysis means an inability to move. Hindlimb paralysis is most common in the rabbit. It can occur suddenly or develop gradually, depending on the cause. Milder disease can cause weakness, this is called paresis.
What causes it?
There are a number of possible causes or paralysis and paresis:
Trauma to the head, spine or limbs
Rabbits have powerful hindlegs and can damage their backs if they resist restraint. A stressed rabbit may kick and twist to escape and fracture their spine. Rabbits can also fall when being picked up or fight with other animals and injure themselves. Rabbits should always be handled gently and carefully with their backs and hindlegs supported.
It is important to distinguish between true paralysis (where the nerves are severed, e.g. following spinal injury) and a “floppy” broken leg where the nerves are fine but the leg doesn’t work because the bones needed for leverage are fractured. Generally, fractures are easier to repair. However, some rabbits have low bone density due to lack of exercise. This makes fracture more likely.
Typically from head trauma or cerebrovascular accident (stroke). Disruption to the motor functions in the brain can result in paralysis. This may affect the face and forelimbs as well as the hindlimbs.
Intervertebral disc disease
The discs between the bones of the back (vertebrae) can degenerate, resulting in part of the disc compressing the spinal cord. This can cause mild pressure resulting in weakness and discomfort or extensive damage resulting in permanent paralysis.
This is usually seen in older rabbits. The vertebrae form new bone and fuse to one another. The back becomes stiff and sore and the nerves leaving the spinal cord are compressed.
Arthritis means joint inflammation. It may be seen in previously damaged joints or in older or obese bunnies. It is painful and restricts activity so muscle loss will occur causing weakness.
The brain and spinal cord can be damaged by bacterial, viral or parasitic infection. Encephalitozoon cuniculi is a protozoan parasite which affects the brain and kidneys, Neurological disease may be seen with weakness, paralysis, seizures and head tilt.
Paralysis may be caused by tumours in the brain or spine.
Any long term illness can cause weakness and muscle loss. Organ failure such as liver or kidney disease, dental disease and chronic infections can all contribute to muscle loss.
Why is it important?
Paralysed rabbits can be in considerable pain. Rabbits hide pain so careful assessment and pain management is essential.
Rabbits need to access food and water, empty their bladder and bowels and groom to stay healthy. Rabbits with hindlimb paralysis may be unable to reach their food and water, causing dehydration and weakness. They may also be at risk of urine scalding and infection from incontinence, or bladder rupture if the bladder cannot empty. The nerve supply to the bladder and bowels can be affected by the disease which affects the hindlimbs. Skin infections can result from poor grooming and an inability to pass and eat caecotrophs can cause severe gastrointestinal disease.
Restricted mobility can result in pressure sores forming and becoming infected. This infection can then spread through the bloodstream making the rabbit very unwell.
How do you know what is going on?
Lethargy, loss of appetite, hiding and changes in temperament In conditions causing gradual paralysis, you may see signs of ill health such as lethargy, loss of appetite, hiding and changes in temperament first.
Hindlimb weakness and changes in mobility may be seen. This can progress to symptoms of complete paralysis. Paralysis may also occur suddenly. Paralysed rabbits will lie down for long periods and drag their hindlegs.
Loss of bladder and bowel function may occur with paralysis, urine may be retained causing a swollen belly or there may be urinary incontinence. Caecotrophs may be stuck to the coat and anus.
What can be done?
Paralysis caused by injury is a veterinary emergency. Handle the rabbit carefully, try to reduce movement in the injured area. Support the rabbit as you lift them into a carrier then use rolled up towels or soft toys to reduce movement.
Your vet will examine your rabbit and administer pain relief. Intravenous fluids may be required if your rabbit is in shock. When the rabbit is stable, X-ray, CT or MRI may be used to image the injured area.
‘Deep pain’ will be assessed to determine the severity of the injury. This test determines whether the nervous system is intact. If the spinal cord is completely severed deep pain is not present and the outlook is grim. If deep pain is present the injury may respond to management. Immediately after injury the area is bruised and swollen and this compresses the spinal cord. As the swelling subsides hindlimb function may return.
The rabbit may be hospitalised for pain management and assisted feeding. Most spinal injuries are treated with anti-inflammatory medication, further pain relief and cage rest. Surgery is only recommended in a minority of cases, where it is likely to significantly change the outcome.
Cage rest involves restricting movement to prevent further injury and allow inflammation to resolve. This may be effective in cases of fracture, stroke and disc disease. In cases with bladder dysfunction it may be necessary to manually empty the bladder 2-3 times a day.
X-ray will reveal if spondylosis, arthritis, deformed vertebrae or a bony tumour is causing paralysis. Pain medication, weight control, gentle exercise and creating an easy environment to live in all help to manage these conditions. Senior diets contain supplements which can help arthritic rabbits.
If infection is suspected then samples of the fluid around the spinal cord can be taken by performing a CSF (cerebrospinal fluid) tap. This fluid is analysed at the laboratory and specific treatment can be tailored to the organism found.
Your vet may treat for E. cuniculi rather than test as a positive test does not prove it is the cause of the paralysis.
Further investigations such as blood tests and ultrasound may be required to rule out organ disease.
What can be done at home?
It is often difficult to predict whether a rabbit with hindlimb paralysis will recover. They need long periods of intensive nursing.
- Assisted feeding may be necessary either by syringe or hand feeding.
- Their enclosure must be flat with no obstacles to food and water.
- Bedding must be soft, absorbent and clean. Litter trays should have low sides.
- The recumbent rabbit may need to be turned 4-10 times daily to prevent pressure sores.
- Manual expression of the bladder may be necessary multiple times per day.
- Caecotrophs should be removed regularly and if possible, fed to the rabbit. Regular washing and grooming to prevent urine scalding and matted hair.
- Regular interaction, play and toys to prevent boredom.
- Medication must be given regularly.
What’s the outcome likely to be?
Hindlimb paralysis can be a devastating condition. It is essential that your rabbit is treated quickly and kept as comfortable as possible. Some rabbits will recover fully with treatment. For those that are paralysed but pain free, a specially designed cart may allow them to move around comfortably.
What can I do to protect my pet?
- Always handle your rabbit carefully.
- Remove any hazards from their hutch and enclosure.
- Schedule regular veterinary health checks.
- Treat any new rabbits for E. cuniculi.
- Feed an appropriate amount of a balanced diet and monitor weight.
- Spend time with your rabbit to ensure that you are familiar with their normal behaviour and activity level so that you are alert to early disease.